What is the difference between these two codes: (the object is any random object)
Object object = anything;
String str = object+"";
and
Object object = anything;
String str = object.toString();
They both return the same String.
How do they performance? Which one is better?
If you decompile these examples using javap -c you will see that in first case
StringBuilder will be created append(Object obj) append(String.valueOf(obj)); null reference. So main difference in result of null
Object o = null;
System.out.println(o + ""); // result "null"
System.out.println(o.toString()); // throws NPE
If your data can't be null or you want to throw NPE you should use toString() for better performance.
If your data can be null and in this case result string should also be "null" String.valueOf(object) will give you better performance than object+"".
The first one is equivalent to:
Object object = anything;
String str = new StringBuilder().append(object).toString();
whereas the second is just a plain toString() call. The performance difference is likely to be negligible, but the second will almost certainly be marginally faster because it doesn't use an unnecessary StringBuilder. Generally, prefer the second approach.
